How do you keep large pieces uniform?

[Mungo]

I'm planning a picture frame mat that may take several days to finish.

Is it correct to case all of the leather, even the completed tooling portions, when beginning a new work session? Won't the stamping start to raise up again with each succesive wetting? Also, do you keep the piece damp by putting it in a plastic bag and stored in the fridge?

[fredk]

You may not need to keep completed areas as wet as needed for tooling but you need to keep it somewhat wet otherwise you'll have tide marks on your leather ie where an area dried differently to another because it dried sooner

I've never had properly stamped or tooled areas rise up again. Yes, you can keep the piece damp that way. If its going to take a few days or more put some mold retarder into the casing water. I use just a few drops of baby bottle steriliser

[Mungo]

Thank you for the response. I've only completed small tooling projects before so I want to get this right.